Material for arc welding



Patented Apr. 24, 1934 UNHTED STATES PATENT OFFICE signor to The LincolnElectric Company,

Cleveland, Ohio, a corporation of Ohio N 0 Drawing.

'7 Claims.

This invention relates as indicated to mate rials for arc welding, andhas specific reference to the employment of certain materials for thepurpose of providing a protective coating over the pool of molten metalformed upon or in the work by the presentation thereto in arcingrelation of a suitable electrode.

It has been well known in the art of electric arc welding that the poolof molten metal formed in the vicinity of the arc area should beprotected by a suitable coating or blanket of fiuxing material eifectiveto exclude the atmosphere from the metal. Numerous materials such asclay have been employed as a coating on the weld rod for supplying thisprotective covering for the pool of molten metal.

All materials which have been employed for the above defined purposehave undesirable characteristics of which those presently to beenumerated are notable examples.-

A prominent characteristic of the coating on the pool of molten metalsupplied by materials heretofore employed is that such coating usuallybreaks up into globules or like particles which float upon the pool ofmolten metal similar to. pieces of wood or like material floating onabody of water.

This segregation of the protective material is objectionable from twomain standpoints. When the coating segregates in the above defined man--such island similarly as a floating block of wood leaves an impressionin the ice as the water is frozen.

Materials of the character heretofore employed having the above namedundesirable characteristics have had a tendency, due to their separationinto floating islands, to collect in ridges along the sides of the seamthereby producing what is commonly termed under-cutting along the sidesof the weld metal.

In order that any fluxing material designed to float upon the pool ofmolten metal shall not form objectionable depressions therein, it isessential that such coating be either of a relatively low specificgravity or porous and fluffy to the ex- Application February 8, 1932,Serial No. 591,757

tent that it will readily come to the surface of the pool of moltenmetal and freely float thereon during solidification of the metal.

After the weld metal has solidified, the flux coating should be readilyand completely removable, so that if an additional layer of weld metalis to be deposited, there will be no flux inclusions in the resultantmetal deposit.

It is among the objects of my invention to provide materials adapted toform a protective flux covering over the pool of the molten metal whichshall have none of the above-named undesirable characteristics, butwhich shall be. distributed over the pool of metal in a uniform film andwhich shall be capable of being quickly and easily removed without theoccurrence thereunder of objectionable under-cuts. Other objects of myinvention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention,then consists of the steps hereinafter fully described and particularlypointed out in the claims, the following description setting forth indetail certain steps embodying the invention, such disclosed stepsconstituting, however, but one of the various ways in which theprinciple of the invention may be used.

Among the materials which I have found to be best suited to the abovedescribed purposes is titanium dioxide, which may be supplied to thepool of molten metal as a layer or coating on the fusible electrodepresented in arcingrelation to the work.. The titanium dioxide may bebound and secured to the surface of the weld .rod by a suitable bindersuch as sodium silicate.

If titanium dioxide is employed merely in combination with sodiumsilicate as a binder, it is noted that the flux covering over the poolof molten metal floats as a uniform film which is not broken up intoseparate islands or globules. Accordingly, there'are no local areas ofdepression' in the metal as the same cools and, hence, when the filmresulting from the use of titanium dioxide is removed, the surface ofthe weld metal is very uniform and free from all under-cutting.

The use of titanium dioxide alone with a suitable binder, such as sodiumsilicate, is, for certain reasons, undesirable, however, due to the factthat the resultant coating on the weld metal adheres so tenaciouslythereto that it is very The substances which I have discovered producethe desired. results are broadly classified as ironcontaining silicatesand magnesium containing silicates.

Chemically pure magnesium silicate produces the desired results but itmay be found more practicable to employ asbestos. Other substances whichI have tried and found to produce successful results are talc, HzMga(SiOs) i; chrysotile, H4Mg3Si209 amosite FeSiOa cro-= cidolite, NaFeSiOa ZLFeSiOs anthophyllite,

Fe,Mg)Si Oa; tremolite, CaMgflSiOaM; actinolite, Ca(Mg,Fe 3 (Si03) 4.

The combination of titanium dioxide with a magnesium-containing silicateor an iron containing silicate or both produces a resultant slag coatingover the weld metal which extends uniformly over the entire area of themetal, thereby aifording complete protection of the metal from theatmosphere. This desirable characteristic of the resultant covering maybe due to a number of reasons, such as the melting point of thisresultant slag, the viscosity of such slag, the surface tension of suchslag, which is so low that there is no segregation into islands, and thefact that the specific gravity of the slag is lower than that of themolten metal. The slag resulting from the above defined coating maylikewise have an effect on the surface tension and fluidity of themolten metal, all of which cooperate in producing the desirable results.

When a slag coating is formed on the molten metal in. the above definedmanner, it will be noted that such coating extends uniformly over thepool while the metal is in its molten state and, due to the uniformityof such film or layer, there will be no local areas in which depressionsoccur in the metal after the same solidifies. The coating formed in thismanner is extremely friable, readily coalescent, very light, and can heexplained, change being made as regards the composition and methodherein disclosed, provided the ingredients or steps stated by any of thefollowing claims or the equivalent of such stated ingredients or stepsbe employed.

I, therefore, particularly point out and distinctly claim as myinvention:

1. A. covered weld-rod for arc welding comprising a metallic rodprovided with an adherent covering including titanium dioxide and amagnesium-containing silicate.

2. A covered weld-rod for are weldingcomprising a metallic rod providedwith. an adherent covering including titanium dioxide and asbestos.

3. A covered Weld-rod for arc welding comprising a metallic rod providedwith an adherent covering including titanium dioxide and anironcontaining silicate.

a. A covered weld-rod for arc welding comprising a metallic rod providedwith an adherent covering including titanium dioxide and at least onesubstance of the group containing iron-com taining silicates andmagnesium-containing silicates.

5. A covered weld-rod for arc welding com- 100 prising a metallic rodprovided with an adherent covering including titanium dioxide and atleast one substance of the group containing magnesium silicate, ironsilicate, asbestos, talc, chrysolite, amosite, crocidolite,anthophyllite, tremolitc, and actinolite.

6. A covered weldrod for arc welding comprising a metallic rod providedwith an adherent covering including a substance containing titan- I iumdioxide, and at least one substance of the group containingiron-containing silicates and magnesiumwontaining silicates.

7. A slag-forming composition for use in electric arc welding comprisingin combination a suostance containing titanium dioxide, and at least onesubstance of the group containing iron-conv y r ad y removed from the Wd a taining silicates and magnesium-containing Other modes of applyingthe principle of my silicates, invention may be employed instead of theone THEOPHIL E. JERABEK.

:DlS-CLAEMER 1,956,327.Theophil. E. Jcrabck, East Cleveland, Ohio.

MATERIAL FOR Anc WELD- ING. Patent dated April 24, 1934. Disclaimerfiled January 19, 1940,

by the assignee,

The Lincoln Electric Company.

Hereby enters this disclaimer to the'claims in said specification asfollows- In each of claims 1, 2, 3, 4:, and 5, we discl claims,respectivel stantial amount of In claim 6 we disclaim an formingconstituent.

which includes, in addition to a halogen-containing compound.

aim any covering set forth in said the constituents named, any suba a ycovering'set forth in said claim which includes in addition to theconstituents named any substantial amount of y a nonsilicious slag- .111claim i we disclaim any composition set forth in said, claim whichincludes, in

addition to theconstituents namedmnysubstantial amount compound.

of a halogen-containing [0min Gazette February 1c, 1940.

